Organic Light Emitting Display (OLED) has gradually become the mainstream of display field with its excellent performances such as low power consumption, high color saturation, wide viewing angle, thin thickness and the ability to achieve flexibility, etc. At present, OLED has been used widely in terminal products such as smartphones, tablets, and televisions, etc. In order to achieve a narrow frame, bond pads are typically fabricated on one side of the substrate, and OLED is bent with very small radius. During bending, since the flexible display substrate still contains a large number of inorganic layers, these inorganic layers are prone to be damaged and cracked, further causing damage and crack of conductive wirings in OLED, and causing performance degradation or even failure of the flexible display substrate and the display device. Therefore, there is a need to improve the damage resistance during bending in the art.